Material handling system transfer assembly

ABSTRACT

An improved material handling system includes a main track for guiding movement of a vehicle to and from aisles between adjacent rows of bins. The vehicle is transferred from the main track to tracks in a selected aisle by operating transfer arms on the vehicle to pivot transfer rails forming lengths of the main track into alignment with the aisle tracks. Once the vehicle has entered the selected aisle and moved beyond the transfer rails, biasing springs pivot the transfer rails back into alignment with the main track where the transfer rails are held in place by latch assemblies. When the vehicle starts to leave the selected aisle and is approaching the main track, the vehicle operates trip linkages to release the latch assemblies. Continued movement of the vehicle toward the main aisle operates other linkages to pivot the transfer rails back into alignment with the aisle tracks against the influence of the biasing springs.

United States Patent 91 Park [ Feb. 13, 1973 1 MATERIAL HANDLING SYSTEM TRANSFER ASSEMBLY [75] Inventor: Richard J. Park, Bountiful, Utah [73] Assignee: Kenway Engineering, Inc., Cleveland, Ohio [22] Filed: Feb. 22, 1971 [21] Appl. No.: 117,422

[52] US. Cl. ..104/88, 104/130 [51] Int. Cl. ..B61b 15/00 [58] Field of Search ....105/l77; 104/88, 96, 99, 100,

Primary Examiner-James B. Marbert Assistant ExaminerD. W. Keen ,Attorney-Yount & Tarolli [5 7] ABSTRACT An improved material handling system includes a main track for guiding movement of a vehicle to and from aisles between adjacent rows of bins. The vehicle is transferred from the main track to tracks in a selected aisle by operating transfer arms on the vehicle to pivot transfer rails forming lengths of the main track into alignment with the aisle tracks. Once the vehicle has entered the selected aisle and moved beyond the transfer rails, biasing springs pivot the transfer rails back into alignment with the main track where the transfer rails are held in place by latch assemblies. When the vehicle starts to leave the selected aisle and is approaching the main track, the vehicle operates trip linkages to release the latch assemblies. Continued movement of the vehicle toward the main aisle operates other linkages to pivot the transfer rails back into alignment with the aisle tracks against the influence of the biasing springs.

8 Claims, 8 Drawing Figures PATENTEDFE813 I973 SHEET 3 OF 4 lA/VEA/ TOR P/C'HARD J PARK MATERIAL HANDLING SYSTEM TRANSFER ASSEMBLY This invention relates generally to a new and improved material handling system and, more particularly, to a system wherein a plurality of vehicles which move along a track system may be utilized to transport materials to and from storage locations.

In automatic warehousing systems, stacker cranes and other vehicles are utilized to transport materials to and from rows of bins. In such a system, a stacker crane moves along tracks within an aisle between a row of bins. When operations are completed in a bin aisle, the stacker crane is moved along a transfer aisle to another bin aisle for operations therein. A particularly advantageous warehousing system of this type is claimed in copending application Ser. No. 117,321, filed by George R. Pipes on Feb. 22, 1971, entitled Material Handling System (Docket No. EY-5l53), and assigned to the assignee of the present application. In the Pipes material handling system, lengths of transfer track are pivoted from a position extending along the transfer aisle to a position extending along a bin aisle to enable the vehicle to enter the bin aisle. When the vehicle has completed operations within the bin aisle and is returning to the transfer aisle, these lengths of track are pivoted back into alignment with the track in the transfer aisle. The pivoting of the tracks is effected by actuators carried on the vehicle.

In the material handling system invented by George R. Pipes, when one of the stacker cranes has entered a bin aisle by pivoting the lengths of transfer track from a position in which they are aligned with the track in the transfer aisle to a position in which they are aligned with the track in the bin aisle, the lengths of transfer track may impede operation of other stacker cranes. This is because the lengths of transfer track are positioned so as to prevent movement of another stacker crane along the transfer aisle past the bin aisle in which the first stacker crane is operating. In addition, the second stacker crane cannot enter the bin aisle where the first stacker crane is operating.

The present invention provides a new and improved material handling system of the type claimed in the afore-mentioned application so that a plurality of stacker cranes may be efficiently utilized therein. In the material handling system claimed in the afore-mentioned application, lengths of transfer track are pivoted from positions extending along a transfer aisle to positions in which they form continuations of tracks in a bin aisle so that a vehicle may move from the transfer aisle to the bin aisle. When the vehicle has entered the bin aisle, the lengths of transfer track are automatically returned to their initial positions extending along the transfer aisle. When the stacker crane has completed its operations within the bin aisle, the lengths of transfer track are automatically swung back into alignment with the bin aisle tracks as the stacker crane moves toward the transfer aisle. Once the stacker crane has moved into the transfer aisle, the lengths of transfer track are moved back to their initial position to guide movement of the stacker crane away from the bin aisle. Since the lengths of transfer track move so they extend along the transfer aisle after the stacker crane has entered a bin aisle, a second stacker crane can be guided past the bin aisle or guided into the bin aisle by these lengths of transfer track. Accordingly, a plurality of stacker cranes may be used efficiently in the same track system.

Accordingly, it is an object of this invention to provide a material handling system of the type claimed in the aforementioned Pipes application wherein provision is made for a plurality of vehicles to operate simultaneously in the system.

Another object of this invention is to provide a new and improved material handling system wherein lengths of transfer track are pivoted by a vehicle to transfer the vehicle from a transfer aisle to a bin aisle and are returned to their initial positions after the vehicle has entered the bin aisle.

Another object of this invention is to provide a new and improved material handling system which includes first and second tracks extending transversely to each other for guiding movement of a plurality of vehicles along transversely extending paths and wherein a transfer rail is movable between a first position in which it is aligned with the first track and a second position in which it is aligned with the second track, the transfer rail being movable from the first position to the second position by an operator arrangement on a vehicle to enable the transfer rail to guide movement of the vehicle from the first track to the second track, the transfer rail being movable from the second position to the first position to guide movement of other vehicles along the first track, the transfer rail being movable from the first position to the second position in response to a vehicle on the second track approaching the first track to guide movement of the vehicle from the second track to the first track.

Another object of this invention is to provide a new and improved material handling system including a length of track which is spring biased to a position in which it is aligned with a first track assembly, an operator arrangement associated with the length of track being actuatable by a vehicle to effect pivoting movement of the length of track into alignment with a second track assembly against the influence of the spring bias.

These and other objects and features of the present invention will become more apparent upon a consideration of the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a schematic illustration of a material handling system which includes a vehicle which is movable from a main aisle extending transversely to a row of bins to an aisle extending along the row of bins;

FIG. 2 is a schematic illustration of a material handling vehicle utilized in the material handling system of FIG. 1;

FIG. 3 is an enlarged plan view, taken generally along line 33 of FIG. 2, illustrating an operator arrangement on the vehicle for use in effecting a transfer of the vehicle from a main track extending along the main aisle to aisle tracks extending along a row of bins;

FIG. 4 is an enlarged plan view of a portion of the operator assembly of FIG. 3 and illustrating the relationship of the operator assembly to a transfer arm when the transfer arm is positioned to engage an aisle track;

FIG. 5 is an elevational view, taken generally along line 5-5 of FIG. 4, illustrating the relationship of the operator assembly and transfer arm to an aisle track;

FIG. 6 is a plan view illustrating a transfer rail assembly constructed in accordance with the present invention and including a latch assembly for retaining a transfer rail in alignment with the main track, a trip assembly for releasing the latch assembly, and a transfer rail swing assembly for effecting movement of the transfer rail into alignment with an aisle track;

FIG. 7 is an elevational view, taken generally along line 7 7 of FIG. 6, further illustrating the relationship between the transfer rail, latch assembly, and transfer rail swing assembly; and

FIG. 8 is a plan view, generally similar to FIG. 6, illustrating the transfer rail in alignment with the aisle track.

A material handling system 10 includes a plurality of rows 12, l4, l6, l8 and of bins 22 for storing materials. Material handling vehicles 26 and 28 move along a transfer or main aisle 30 which extends perpendicular to the rows 12-20 of bins. When a material handling vehicle is adjacent to a selected bin or secondary aisle, such as the aisle 32 between the rows 14 and 16 of bins or the aisle 34 between the rows 18 and 20 of bins, the material handling vehicle moves from the transfer or main aisle 30 down the bin or secondary aisle until it is adjacent to a selected bin. In the illustrated embodiment of the invention, the material handling vehicles 26 and 28 are stacker cranes (see FIG. 2) each of which includes a shuttle assembly 38 which is cxtendable to position a container 40 in a selected bin. Of course, the stacker cranes 26 and 28 can be utilized to retrieve containers, such as the container 40, from a selected bin. Although the transfer aisle 30 is referred to herein as the main aisle, it ,should be understood that the stacker cranes 26 and 28 perform work operations in the bin aisles 32 and 34 which are referred to herein as secondary aisles.

The stacker crane 26 is of a known construction and rides on a cushion of air blown against a floor or other surface 44, as is known, (see FIGS. 2 and 3). Of course, other known drive arrangements could be utilized if desired and the present invention is not limited to any particular drive arrangement. The stacker crane 26 includes a rectangular frame or base 50 with an upwardly extending mast 52 which engages a track arrangement 54 on the ceiling 56 of a building to prevent the mast from tipping. The ceiling track 54 is interrupted at the bin or secondary aisles 32 and 34 to enable the stacker crane 26 to move from the transfer or main aisle 30 into the bin aisle.

The shuttle assembly 38 is movable vertically up and down along the mast 52 to position the container 40 vertically relative to a bin 22 which is to receive the container. Suitable power tracks can be provided adjacent either the base frame 50 or the ceiling track arrangement 54 to transmit electrical power to motors within a body 58 of the stacker crane 26. The stacker crane 28 is of the same generally known construction as the stacker crane 26 and will not be further described herein to avoid prolixity of description.

Although the stacker cranes 26 and 28 have a trackless" drive directly to the floor 44, a transfer or main track 62 is engaged by the stackercranes to guide their movement in the direction of the arrows 64 along the transfer or main aisle 30. Similarly, secondary or aisle tracks 66, 68, 70 and 72 are disposed along the rows of bins 14-20 to guide movement of the stacker cranes 26 and 28 along the aisles 32 and 34 in a direction perpendicular to the transfer or main aisle 30. It should be noted that the aisle tracks 66-72 terminate 5 just short of and do not intersect the main track 62.

Transfer assemblies 76 and 78, constructed in accordance with the present invention, are operated by the stacker cranes 26 and 28 to guide their movement from the transfer or main track 62 to the secondary or aisle tracks 66-72 when the stacker cranes enter the bin or secondary aisles 32 and 34. The transfer assemblies 76 and 78 include transfer rails 80, 82, 84 and 86 formed of straight lengths of the main track 62. The transfer rails 8086 normally or initially span the secondary aisles 32 and 34 so as to guide movement of the stacker cranes 26 and 28 along the main aisle 30 past the entrances to the secondary aisles. When a stacker crane is to enter a secondary aisle 32 or 34, the stacker crane moves into alignment with the entrance to the selected secondary aisle. The transfer rails are then moved into alignment with the tracks in the selected secondary aisle to guide movement of the stacker crane from the main aisle into this secondary aisle.

The track lengths or transfer rails 84 and 86 are shown in FIG. 1 spanning the secondary aisle 34 to guide movement of the stacker crane 28 along the main aisle 30 past the entrance to the secondary aisle 34. On the other hand, the track lengths or transfer rails 80 and 82 are shown pivoted from their aisle spanning positions to a transfer position in which they extend parallel to the longitudinal axis of the secondary or aisle tracks 66 and 68 to guide movement of the stacker crane 26 from the main aisle 30 to the secondary aisle 32. Of course, once the stacker crane enters the secondary aisle 32, the aisle or secondary tracks 66 and 68 guide movement of the stacker crane along the aisle 32, that is in the direction of the arrows 90. After the stacker crane 26 has entered the secondary aisle 32, the transfer rails 80 and 82 are advantageously pivoted back to their aisle spanning positions in which they can guide movement of the stacker crane 28 along the main aisle 30 past the entrance to the secondary aisle 32.

The stacker crane 26 includes a pair of transfer arms 102 and 104 which engage the main track 62 and are pivotal to move the transfer rails 80 and 82 or 84 and 86 into alignment with their associated aisle tracks. The transfer arms 102 and 104 are pivotally mounted at 106 and 108 (FIG. 3) on the frame 50 of the stacker crane 26. A drive assembly 112 is connected with the transfer arms 102 and 104 to effect pivoting movement of the transfer arms and transfer rails engaged by the arms.

The drive assembly 112 includes a drive linkage 114 which is driven by a motor 116 (see FIGS. 4 and 5) through a gear reduction unit 118 to pivot the transfer arm 102 in a clockwise direction (as viewed in FIG. 3) about its mounting 106. Simultaneously with this movement of the transfer arm 102, the drive assembly 112 pivots the transfer arm 104 in a counter clockwise direction (as viewed in FIG. 3) about its mounting 108. Since the transfer rails 80 and 82 are engaged by the arms 102 and 104, this pivotal movementof the arms moves the transfer rails 80and 82 from their aisle spanning positions extending across the secondary aisle 32 to their transfer positions extending parallel to the aisle tracks 66 and 68 (see FIG. 1). Thus, the transfer arms 102 and 104 are pivotal from positions extending outwardly of the stacker crane 26 to positions beside the frame 50 of the stacker crane to move the transfer rails 80 and 82 into alignment with the aisle tracks 66 and 68. However, it should be understood that the transfer arms 102 and 104 could be mounted for movement from a position extending along the front of the frame 50 to an outwardly extending position to pivot the transfer rails 80 and 82 into alignment with the aisle tracks 66 and 68. In addition, it should be understood that although a pair of transfer arms 102, 104 have been illustrated herein to pivot a pair of relatively short transfer rails 80 and 82, a single transfer arm could be mounted on the stacker crane 26 to pivot a single relatively long transfer rail.

The transfer arms 102 and 104 are held in a position extending parallel to the longitudinal axis of the main track 62, that is in the position of transfer arms 122 and 124 of the stacker crane 28 in FIG. 1, by a pair of struts 128 and 130 (FIG. 3). The struts 128 and 130 are pivotally connected at 138 to a slide block 140 which is movable along a channel 142 defined between a pair of guides 144 and 146 mounted on the frame 50. The inner end portion of the strut 130 is connected to the frame 50 in the same manner as in which the strut 128 is connected with the frame.

When the stacker crane 26 is moving along the main track 62 with the transfer arms 102 and 104 extending parallel to the longitudinal axis of the main track, the transfer arms interconnect the stacker crane and the main track. Since the main track 62 guides movement of the stacker crane 26 along the main aisle 30, it is important that the transfer arms 102 and 104 be held against pivotal movement relative to the frame 50 of the stacker crane. Accordingly, a latch assembly 154 engages the slide block 140 to retain the strut 128 against movement along the channel 142. When the transfer arm 102 is to be pivoted inwardly toward the frame 50 of the vehicle by operation of the drive assembly 112, a release solenoid 156 on the frame 50 is energized to operate the latch assembly 154 and release the slide block '140 for movement along the channel 142 in the direction of the arrow 160. This enables the transfer arm 102 to be pivoted in a clockwise direction toward the frame 50 of the stacker crane 26 by the drive assembly 112. Of course, a latch assembly and solenoid, similar to the latch assembly and solenoid 154 and 156, are associated with the strut 130 to hold the transfer arm 104 against pivotal movement when the stacker crane 26 is moving along the main track 62.

The drive assembly 112 is operable to simultaneously pivot the transfer arms 102 and 104 and the transfer rails 80 and 82 through ninety degrees relative to the frame 50 of the stacker crane 26. Accordingly, the linkage 114 of the drive assembly 112 includes a swivel plate 170 which is rotatable relative to the frame 50 by a drive or output shaft 172 (FIGS. 3, 4 and 5) of the gear reducer 118. Rotational movement of the swivel plate 170 moves pivot arms 176 and 178 to rotate crank arms 180 and 182 through ninety degrees. Of course, this rotational movement of the crank arms 180 and 182 pivots support pins 184 and 186 which are connected to the transfer arms 102 and 104. The interconnection between the support pin 184 and the transfer arm 104 includes a connector plate 190 (FIG. 5) which is fixably connected to the transfer arm 104 and the support pin 184. Although only the mounting for the transfer arm 104 on the support pin 184 is illustrated herein, it should be understood that the transfer arm 102 is mounted on the support pin 186 in the same manner.

From the foregoing, it can be seen that the stacker crane 26 includes a pair of transfer arms 102 and 104 which extend parallel to and engage the main track 62 with rollers, similar to rollers 196 and 198 of FIG. 5, to guide movement of the stacker crane along the main aisle 30. When the stacker crane 26 reaches the entrance to a selected secondary aisle, such as the aisle 32, the transfer arms 102 and 104 are pivoted through 90 toward the frame 50 of the stacker crane by the drive assembly 112. This movement of the transfer arms 102 and 104 pivots the transfer rails and 82 into alignment with the aisle tracks 66 and 68. When the transfer rails 80 and 82 have been pivoted into alignment with the aisle tracks 66 and 68, the stacker crane is moved forward along the aisle 32. As the stacker crane 26 moves along the aisle 32, the rollers on the transfer arms 102 and 104 move out of engagement with the transfer rails 80 and 82 and into engagementwith the aisle tracks 66 and 68. Although the transfer arms 102 and 104 have been described herein in connection with the stacker crane 26, it is contemplated that they could be used in association with other types of material handling vehicles.

In accordance with the present invention, a separate transfer rail swing or operator assembly is associated with each of the pivotal transfer rails 80-86 to move the associated transfer rail between the initial position and the transfer position. Thus, a transfer rail swing or operator assembly 210 (see FIGS. 6, 7 and 8) is associated with the transfer rail 82 to effect movement of the transfer rail between the initial position in which it is aligned with the main track62 (FIGS.6 and 7) and a second or transfer position in which the transfer rail 82 is aligned with the aisle track 68 (FIG. 8). As was previously explained, the transfer arms 102 and 104 on the stacker crane 26 pivot the transfer rail 82 from the initial position in which it forms part of the main track 62 to the transfer position in which it is aligned with the aisle track 68. However, the swing or operator assembly 210 pivots the transfer rail 82 back into alignment with the main track 62 once the stacker crane 26 has entered the secondary aisle 32. This enables the transfer rail 82 to guide movement of another stacker crane, for example the stacker crane 28, along the main aisle 30 while the stacker crane 26 is in the secondary aisle 32. When the stacker crane 26 approaches the main aisle 30 to leave the secondary aisle 32, the transfer rail swing or operator assembly 210 pivots the transfer rail 82 back into alignment with the aisle track 68 to enable the transfer rail 82 to guide movement of the stacker crane 26 as it returns to the main aisle 30.

The transfer rail 82 is held or retained in alignment with the longitudinal axis of the main track 62 by a latch assembly 214 which is mounted on a support frame 216 extending along the main aisle 30. The latch assembly 214 includes a retaining latch or pawl 220 which is pivotally mounted on the support frame 216 for movement between an engaged or latched position and a release position. When it is in the latched position, the latch pawl 220 engages the rail 82 to hold the rail against pivotal movement relative to the main track 62. When the latch pawl 220 is released, a retaining nose or end portion 222 of the latch pawl is raised upwardly (from the position shown in FIG. 7) to clear the transfer rail 82 so that it is free to move into alignment with the aisle track 68 (see FIG. 8).

As the stacker crane 26 moves along the main track 62 into alignment with the entrance to the secondary aisle 32, the latch pawl 220 is pivoted upwardly by camming engagement of the transfer arm 104 with the nose 222 of the latch pawl. This releases the latch assembly 214. The transfer arm 104 is then moved inwardly toward the frame 50 of the stacker crane 26 by operation of the drive assembly 112 in the manner previously explained. Since the rollers 196 and 198 engage the transfer rail 82 (FIG. this movement of the transfer arm 104 pivots the transfer rail 82 in a counter clockwise direction (as viewed in FIG. 6) about a pivot mounting 230. This results in the transfer rail 82 moving out of alignment with the main track 62, through the position shown in FIG. 3, and to the transfer position (FIG. 8) in which the transfer rail is aligned with the aisle track 68. Of course, the transfer rail 80 is pivoted simultaneously with the transfer rail 82 by the transfer arm 102 of the stacker crane 26 (FIG. 3).

Once the transfer rails 80 and 82 have been moved into alignment with the aisle tracks 66 and 68, the stacker crane 26 can enter the aisle 32. It should be noted that the stacker crane 26 moves along the main aisle 30 in a direction parallel to its transverse axis 231 (see FIG. 1) and then moves along the secondary aisle 32 in a direction parallel to its longitudinal axis 232. However, the transfer arms 102 and 104 engage guide tracks to guide movement of the stacker crane 26 along either the main aisle 30 or the secondary aisle 32. Thus, the transfer arms 102 and 104 extend parallel to the axis 231 and the main track 62 when the stacker crane 26 is moving along the main aisle 30. Similarly, when the stacker crane 26 is moving along the secondary aisle 32, the transfer arms 102 and 104 extend parallel to the longitudinal axis 232 of the stacker crane and engage the aisle tracks 66 and 68 to guide movement of the stacker crane along these tracks.

Once the stacker crane has entered the secondary aisle 32 and has moved a short distance beyond the transfer rail 82, a biasing spring 240 pivots the transfer rail from the transfer position of FIG. 8 to the initial position of FIG. 6. The biasing spring 240 extends between a stationary support bracket 242 and a crank arm 244 which is connected to the pivot mounting 230 for the transfer rail 82. When the transfer rail 82 is pivoted from the initial position to the transfer position immediately prior to entrance of the stacker crane 26 into the secondary aisle 32, the crank arm 244 is pivoted in a counter clockwise direction from the position shown in FIG. 6 to the position shown in FIG. 8 with a resulting stretching of the biasing spring 240. Therefore, when the trailing end of the stacker crane 26 has moved a short distance beyond the transfer rail 82, the biasing spring 240 pivots the crank arm 244 and transfer rail 82 in a clockwise direction about the pivot mounting 230 to move the transfer rail into alignment with the main track 62. Of course, the latch assembly 214 will then engage the transfer rail 82 to retain it in alignment with the main track 62.

When the stacker crane 26 leaves the aisle 32, the transfer rail 82 must be swung or pivoted out of alignment with the main track 62 and into alignment with the aisle track 68 to guide movement of the stacker crane out of the aisle 32. Accordingly, when the stacker crane 26 approaches the main aisle 30, a trip assembly 250 is actuated to operate the latch assembly 214 and release the transfer rail 82 for movement about the pivot mounting 230. Continued movement of the stacker crane toward the main aisle 30 actuates a swing operator assembly 252 to effect pivotal movement of the transfer rail 82 from the initial position (FIG. 6) to the transfer position shown (FIG. 8). Thus, the transfer rail 82 is moved from a position in which it is aligned with the main track 62 (FIG. 6) to a position in which it is aligned with the aisle track 68 (FIG. 8) against the influence of the biasing spring 240 in response to movement of the stacker crane 26 along the aisle 32 toward the main aisle 30.

The trip assembly 250 for releasing the latch assembly 214 includes a trip arm 258 which is pivotally mounted on a support bracket 260 and is movable to the actuated position of FIG. 8 to release the latch assembly 214. The trip arm 258 is connected with the latch assembly 214 by a flexible cable 262. The flexible cable 262 is in turn connected to a latch trip plate or bar 266 (FIG. 7) which is pivotally mounted at 268 on a support bracket 270. The trip plate or bar 266 is connected with the latch pawl 220 by a link 274.

When the stacker crane 26 moves along the aisle 32 toward the main aisle 30, the stacker crane engages the trip arm 258 which extends into the aisle 32 (see FIG. 6). Continued movement of the stacker crane 26 toward the main aisle 32 pivots the trip arm 258 to its actuated position (FIG. 8). Moving the trip arm 258 to its actuated position causes the cable 262 to rotate the trip plate 266 in a clockwise direction (as viewed in FIG. 7) about its pivot mounting 268. This rotational movement of the trip plate 266 is transmitted by the link 274 to the latch pawl 220 to thereby rotate the latch pawl in a counter clockwise direction (as viewed in FIG. 7) about its pivot mounting 280 against the influence of a biasing spring 282. This pivotal movement of the latch pawl 220 releases the transfer rail 82 for pivoting movement from its initial position (FIG. 6) to the transfer position (FIG. 8).

Still further movement of the stacker crane toward the main aisle 30 results in the swing or operator assembly 252 being actuated by the stacker crane to pivot the transfer rail 82 from the initial position to the transfer position against the influence of the biasing spring 240. Thus, the operator assembly 252 includes a swing bar 286 which is pivotally mounted at 288 on a generally V-shaped support bracket 292. The support bracket 292 includes a pair of legs 294 and 296 (see FIGS. 6, 7 and 8) which are connected to a mounting plate 300 secured to the aisle track 68. A trip or actuator arm 304 is pivotally mounted at 306 on the swing arm 286 and is biased against a detent or stop 308 by a spiral spring 312. This mounting enables the actuator arm 304 to move the swing arm 286 in only a clockwise direction about the pivot mounting 288.

When a leading end portion of the stacker crane 26 engages the actuator arm 304 as it moves toward the main aisle 30, the actuator arm causes the swing or operator bar 286 to pivot in a clockwise direction (as viewed in FIG. 6) to the actuated position shown in FIG. 8. This pivotal movement of the swing or operator bar 286 is transmitted to the crank arm 244 by a connector rod 316 to rotate the crank arm 244 and transfer rail 82 through 90 from the initial position (FIG. 6) to the transfer position (FIG. 6) against the influence of the biasing spring 240.

Once the transfer rail 82 has been moved to the transfer position, continued movement of the stacker crane 26 toward the main aisle 3%) moves rollers 318 (FIG. 2) out of engagement with the aisle track 68 and into engagement with the transfer rail 82. Continued movement of the stacker crane 26 toward the main aisle 30 moves the rollers 196 and 198 on the transfer arm 104 into engagement with the transfer rail 82 (FIG. 5). Once the stacker crane 26 has moved into the main aisle (FIG. 1), the transfer arms 102 and 164 on the stacker crane 26 are pivoted to move the transfer rails 80 and 82 from the transfer positions (FIG. 1) to their initial positions spanning the aisle 32. As the transfer rails 80 and 82 are swung into their initial positions by the transfer arms 104, the transfer rails will be engaged by latch assemblies, similar to the latch assembly 214 (FIG. 7). This retains the transfer rails 80 and 82 against pivotal movement as the stacker crane 26 moves along the main track 62. Once this has occurred, the stacker crane 26 is free to move along the main aisle 30 in the direction of the arrows 64.

Although only the transfer rail swing or operator assembly 210 associated with the transfer rail 82 has been fully described herein, it should be understood that a similar operator assembly is associated with the transfer rail 80. Therefore, the transfer rails 80 and 82 are moved together in unison by their associated operator assemblies to swing the transfer rails back to their initial positions spanning the aisle 32 once the stacker crane 26 has entered the aisle 32. In addition, the transfer rail 80 is swung to its transfer position (see FIG. I) by operation of a swing or operator assembly of the same construction as the swing operator assembly 252, at the same time that the transfer rail 82 is swung to its transfer position. In addition, it should be understood that transfer rail swing or operator assemblies, of the same construction as the transfer rail swing assembly 210 of FIG. 8, are associated with the transfer rails 84 and 86 to move them in the same manner as previously explained in connection with the transfer rails 80 and 82.

In view of the foregoing remarks, it can be seen that the material handling system 10 includes a main track 62 for guiding movement of the stacker cranes 26 and 28 in the direction of the arrows 66. Transfer rails 80, 82, 84 and 86 are mounted in pairs in association with the secondary aisles 32 and 34. The transfer rails are pivotal between an initial position in which they are aligned with the main track 62 and a transfer position in which they are aligned with the associated aisle tracks 66, 68, and 72. When a stacker crane, such as the stacker crane 26, is to move from the main aisle 30 to a secondary aisle, the stacker crane is aligned with the entrance to the aisle and the transfer arms 102 and lit) 10-6 on the stacker crane are pivoted to swing the transfer rails into alignment with the aisle tracks. The stacker crane 26 then moves down the secondary aisle. When the stacker crane 26 has cleared the swing or pivot arm 286 of the transfer rail swing assembly 210, the biasing spring 240 will swing the associated transfer rail back into alignment with the main track 62.

When the stacker crane 26 is to leave the secondary aisle, the stacker crane operates the latch assembly 250 to release the latch 214. The stacker crane 26 then actuates the swing or operator assembly 252 to pivot the associated transfer rail about the pivot mounting 230 into alignment with the aisle track 62. Once the stacker crane 26 has moved into the main aisle 30, the transfer arms 102 and 104 on the stacker crane are operated to swing the transfer rails and 82 back to their aisle spanning positions so that the stacker crane is free to move along the main aisle. Although only the transfer arms 102 and 164 for the stacker crane 26 have been fully described herein, it should be understood that the transfer arms 122 and 124 on the stacker crane 28 are of the same construction and operate in the same manner as do transfer arms I02 and 104.

Having described specific preferred embodiments of the invention, the following is claimed:

1. A material handling system comprising a floor supported vehicle for use in moving materials, first and second track means extending transversely to each other for guiding movement of said vehicle along transversely extending paths along said floor, a length of track movable between a first position in which it is continuously aligned only with said first track means and a second position in which said length of track is continuously aligned only with said second track means, means on said vehicle for effecting movement of said length of track from said first position to said second position to enable said length of track to guide movement of said vehicle along one of the paths and then along the other of the paths, and means on said second track means for effecting movement of said length of track from said second position to said first position in response to movement of said vehicle to a position along said second track means.

2. A material handling system as set forth in claim 1 further including operator means for effecting movement of said length of track from said first position to said second position in response to movement of said vehicle along said second track means in a direction toward said first track means to thereby effect a positioning of said length of track to said second position to guide continued movement of said vehicle toward said first track means.

3. A material handling system as set forth in claim 2 further including latch means for holding said length of track in said first position and actuator means for operating said latch means to release said length of track in response to movement of said vehicle along said second track means toward said first track means to enable said operator means to effect movement of said length of track from said first position to said second position.

4. A material handling system as set forth in claim 2 wherein said means for effecting movement of said length of track from said second position to said first position includes spring means for urging said length of track toward said first position and said operator means includes linkage means for effecting movement of said length of track from said first position to said second position against the influence of said spring means.

5. A material handling system as set forth in claim 4 wherein said linkage means includes an actuator lever which extends into said other path and is movable along said other path toward said one path by said vehicle to effect operation of said linkage means to move said length of track from said first position to said second position.

6. A material handling system comprising first and second track means extending transversely to each other for guiding movement of a floor supported vehicle along transversely extending paths, a length of track pivotal between a first position in which it is continuously aligned only with said first track means and a second position in which it is continuously aligned only with said second track means, biasing means for urging said length of track toward said first position, operator means actuatable by a vehicle as it moves along said second track means toward said first track means to effect pivotal movement of said length of track from said first position to said second position against the influence of said biasing means, latch means for retaining said length of track in said first position, and mechanical actuator means operable by a vehicle as it moves along said second track means toward said first track means to release said latch means prior to actuation of said operator means by the vehicle to thereby actuate said latch means and release said length of track for movement from said first position to said second position.

7. A material handling system as set forth in claim 6 wherein said operator means includes an actuator lever which projects into a path of movement of the vehicle along second track means, said actuator lever being movable by the vehicle in a direction toward said first track means to effect pivoting movement of said length of track from said first position to said second position, said actuator lever being ineffective to effect movement of said length of track in response to movement of said actuator lever in a direction away from said first track means by the vehicle.

8. A material handling system as set forth in claim 6 wherein said operator means includes linkage means for effecting movement of said length of track from said first position to said second position against the influence of said biasing means, said linkage means including a lever which extends into the path of movement of the vehicle as it moves along said second track means, said lever being pivoted by the vehicle as it moves along said second track means toward said first track means to effect movement of said length of track from said first position to said second position.

t II UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,715,992 Dated February 13, 1973 Inventor-( J. Park It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet, in the heading, item should read as follows: Assignee: Eaton Corporation, Cleveland,

Ohio a corporation of Ohio Signed and sealed this 30th day of April 19714..

(SEAL) Attest:

EDWARD I*I.FLETCIER,JR.

Commissioner of Patents 1 FORM PO-IOSO (10-69) USCOMM-DC 60376-P69 a urs. GOVERNMENT PRINTING o nc: I969 o-aes-saq. 

1. A material handling system comprising a floor supported vehicle for use in moving materials, first and second track means extending transversely to each other for guiding movement of said vehicle along transversely extending paths along said floor, a length of track movable between a first position in which it is continuously aligned only with said first track means and a second position in which said length of track is continuously aligned only with said second track means, means on said vehicle for effecting movement of said length of track from said first position to said second position to enable said length of track to guide movement of said vehicle along one of the paths and then along the other of the paths, and means on said second track means for effecting movement of said length of track from said second position to said first position in response to movement of said vehicle to a position along said second track means.
 1. A material handling system comprising a floor supported vehicle for use in moving materials, first and second track means extending transversely to each other for guiding movement of said vehicle along transversely extending paths along said floor, a length of track movable between a first position in which it is continuously aligned only with said first track means and a second position in which said length of track is continuously aligned only with said second track means, means on said vehicle for effecting movement of said length of track from said first position to said second position to enable said length of track to guide movement of said vehicle along one of the paths and then along the other of the paths, and means on said second track means for effecting movement of said length of track from said second position to said first position in response to movement of said vehicle to a position along said second track means.
 2. A material handling system as set forth in claim 1 further including operator means for effecting movement of said length of track from said first position to said second position in response to movement of said vehicle along said second track means in a direction toward said first track means to thereby effect a positioning of said length of track to said second position to guide continued movement of said vehicle toward said first track means.
 3. A material handling system as set forth in claim 2 further including latch means for holding said length of track in said first position and actuator means for operating said latch means to release said length of track in response to movement of said vehicle along said second track means toward said first track means to enable said operator means to effect movement of said length of track from said first position to said second position.
 4. A material handling system as set forth in claim 2 wherein said means for effecting movement of said length of track from said second position to said first position includes spring meanS for urging said length of track toward said first position and said operator means includes linkage means for effecting movement of said length of track from said first position to said second position against the influence of said spring means.
 5. A material handling system as set forth in claim 4 wherein said linkage means includes an actuator lever which extends into said other path and is movable along said other path toward said one path by said vehicle to effect operation of said linkage means to move said length of track from said first position to said second position.
 6. A material handling system comprising first and second track means extending transversely to each other for guiding movement of a floor supported vehicle along transversely extending paths, a length of track pivotal between a first position in which it is continuously aligned only with said first track means and a second position in which it is continuously aligned only with said second track means, biasing means for urging said length of track toward said first position, operator means actuatable by a vehicle as it moves along said second track means toward said first track means to effect pivotal movement of said length of track from said first position to said second position against the influence of said biasing means, latch means for retaining said length of track in said first position, and mechanical actuator means operable by a vehicle as it moves along said second track means toward said first track means to release said latch means prior to actuation of said operator means by the vehicle to thereby actuate said latch means and release said length of track for movement from said first position to said second position.
 7. A material handling system as set forth in claim 6 wherein said operator means includes an actuator lever which projects into a path of movement of the vehicle along second track means, said actuator lever being movable by the vehicle in a direction toward said first track means to effect pivoting movement of said length of track from said first position to said second position, said actuator lever being ineffective to effect movement of said length of track in response to movement of said actuator lever in a direction away from said first track means by the vehicle. 